Three Bears - Grizzly Bear, Polar Bear, Black Bear from “Bears in the Wild” by Ada and Frank Graham - PC-17, ©1981, Box: 5, Folder: 32, item: 4. Natural History Art and Illustration by D. D. Tyler, MS 337. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/310626 Accessed June 19, 2025.